docs: def add_results(self, *rvs, **kwargs):
          """
          Changes the state to reflect the mutation which yielded the given
          result.
  
          In order to use the result, the `fetch_mutation_tokens` option must
          have been specified in the connection string, _and_ the result
          must have been successful.
  
          :param rvs: One or more :class:`~.OperationResult` which have been
              returned from mutations
          :param quiet: Suppress errors if one of the results does not
              contain a convertible state.
          :return: `True` if the result was valid and added, `False` if not
              added (and `quiet` was specified
          :raise: :exc:`~.MissingTokenError` if `result` does not contain
              a valid token
          """
          if not rvs:
              raise MissingTokenError.pyexc(message='No results passed')
          for rv in rvs:
              mi = rv._mutinfo
              if not mi:
                  if kwargs.get('quiet'):
                      return False
                  raise MissingTokenError.pyexc(
                      message='Result does not contain token')
              self._add_scanvec(mi)
          return True